Dab tsi yog Qhov Tseem Ceeb Ntawm Cov Khoom Siv Dej Txias Dej?

Concrete water reducers yog ib qho ntawm feem ntau siv pob zeb sib xyaw. Cov txheej txheem muaj feem cuam tshuam tau hais meej meej cov ntsiab lus, kev faib tawm, thiab cov ntsuas kev sib raug zoo ntawm cov dej txo qis, uas yuav tsis tau tham hauv tsab xov xwm no. Muaj ntau qhov kev cia siab rau cov dej txo qis, xws li txo kev siv dej, ua kom muaj zog, txhim kho cov dej ntws, thiab txuag cov cement (cov ntaub ntawv khi). Tsis tas li ntawd, nws xav tias cov dej reducers tuaj yeem hais txog ntau yam teeb meem kev ua haujlwm xws li tiv thaiv kev sib cais, los ntshav, thiab kev tawg ntawm cov pob zeb tshiab tshiab, thiab txawm daws teeb meem poob poob. Cov kev cia siab no qhia txog kev nkag siab yuam kev ntawm kev ua haujlwm ntawm cov dej reducers. Yog li ntawd, cov kab lus no yog lub hom phiaj los tham txog cov ntsiab lus ntawm cov dej reducers, yuav ua li cas siv lawv, thiab yuav ua li cas saib lub luag haujlwm ntawm ntau yam kev qhia ntawm cov dej reducers.

Lub luag haujlwm dab tsi ua cov dej txo qis ua si hauv pob zeb?Hauv cov ntsiab lus kev kawm, cov dej txo qis yog hu ua Plasticizers, txhais tau tias lawv yog cov khoom sib xyaw uas muab cov yas rau cov pob zeb sib xyaw tshiab. Cov dej hauv cov pob zeb sib tov ua haujlwm rau ob lub hom phiaj: ib qho yog rau cov tshuaj tiv thaiv dej, uas yuav tsum tau muaj dej tsawg heev. Nws yog kwv yees tias kom ua tiav cov tshuaj tiv thaiv ntawm tag nrho cov ntaub ntawv khi, cov dej yuav tsum tau tsuas yog {{0}}.25 npaug ntawm tag nrho cov ntaub ntawv khi. Qhov no txhais tau hais tias nyob rau hauv cov dej-rau-cement piv, tsuas yog 0.25 ntawm cov dej yog siv rau hydration tshua. Daim duab no tseem yog overestimated vim tias cov txheej txheem hydration qeeb heev; Nws paub tias txawm tias tom qab 60 xyoo ntawm kev kho, tseem muaj cov cement uas tsis muaj dej nyob hauv cov qauv pob zeb. Yog li ntawd, thaum lub sij hawm ua vaj tse, tus nqi ntawm cov dej siv los ntawm cov tshuaj tiv thaiv yog tsawg heev. Feem ntau ntawm cov dej hauv pob zeb yog siv los muab cov dej ntws tawm, muab cov pob zeb ua kom zoo nkauj thiab ua kom yooj yim rau kev lis kev cai thiab ua rau cov qauv xav tau. Nws tsis yog ib qho exaggeration hais tias tag nrho cov dej nyob rau hauv pob zeb thaum lub sij hawm tsim kho theem muab flowability rau cov pob zeb.

Puas muaj lwm yam khoom uas tsis yog dej uas tuaj yeem muab cov yas rau pob zeb?Yeej tsis yog. Qee tus tuaj yeem nug seb cov dej txo qis tuaj yeem ua rau kom muaj dej txaus.Vim li cas nws thiaj li hais tias tsis muaj lwm yam khoom siv raw li cov dej tuaj yeem muab cov dej ntws mus rau pob zeb?Qhov no yog ib tug misconception. Peb hais tias dej muab plasticity rau pob zeb yam tsis muaj kev tsis lees paub tias cov dej txo qis tuaj yeem ua kom cov yas tuaj yeem ua kom zoo dua. Ntxiv qhov tsim nyog tus nqi ntawm cov dej reducer rau cov pob zeb ua kom tsis muaj kev poob siab nce nws cov dej ntws. Txawm li cas los xij, yog tias peb tsis ntxiv cov dej txo qis tab sis hloov cov dej kom tsim nyog, qhov ntws tau, thiab yog li plasticity, kuj yuav nce ntxiv. Tab sis yog tias tsis muaj dej hauv cov pob zeb, txawm tias muaj dej ntau npaum li cas ntxiv, cov khoom siv tsis tuaj yeem ntub dej, thiab kev sib txhuam ntawm cov khoom tseem siab, tawm hauv cov pob zeb ua cov xuab zeb xoob tsis muaj plasticity. Raws li qhov no, nws tuaj yeem txiav txim siab tias cov dej txaus tuaj yeem ntub qhov chaw ntawm cov khoom siv raw, txo kev sib txhuam ntawm cov khoom, thiab yog li muab plasticity rau cov pob zeb; qhov sib ntxiv ntawm cov dej reducers amplifates cov nyhuv ntawm dej. Hauv qhov kev nkag siab no, ntxiv cov dej txo qis yog sib npaug rau kev ntxiv dej.

Txij li lub luag haujlwm tseem ceeb ntawm cov dej txo qis yog txhawm rau ua kom cov dej ntws ntawm cov pob zeb ua kom muaj zog, peb tuaj yeem piav qhia cov lus thov tias cov dej txo qis tuaj yeem txo cov dej siv, ua kom muaj zog, thiab txuag cov cement?

Txij li cov dej reducers amplify cov nyhuv ntawm cov dej, yog tias peb tsis xav ua kom cov flowability ntawm cov pob zeb, peb tuaj yeem txo cov dej siv, los yog txo cov dej siv kom tsawg dua kom txo tau qhov nce hauv flowability. Qhov no yog dej-txo cov nyhuv ntawm cov dej reducers.

Peb paub tias lub zog pob zeb yog cuam tshuam los ntawm qhov sib piv ntawm dej-rau-cement; qhov siab dua qhov piv, qhov qis zog, thiab vice versa. Yog tias peb ntxiv cov dej reducer rau cov pob zeb thiab txo cov dej siv thaum tswj cov dej ntws zoo tib yam thiab tib cov ntaub ntawv khi, cov dej-rau-cement piv yuav txo qis, yog li ua kom lub zog ntawm cov pob zeb. Yog tias peb txo cov dej thiab cov ntaub ntawv sib khi thaum tuav cov dej-rau-cement piv thiab flowability, peb tuaj yeem txuag cov ntaub ntawv khi. Qhov no yog txoj kev siv cov dej txo qis, tsis yog lawv cov ntsiab lus. Yog vim li cas yog vim li cas peb siv cov khoom ntawm cov dej reducers los hloov cov pob zeb sib xyaw ua ke, yog li ua kom muaj zog lossis txuag cov ntaub ntawv khi. Xav txog C50 kev sib xyaw ua ke: kom ua tau raws li qhov xav tau ntawm lub zog, qhov sib piv ntawm cov dej-rau-cement yuav tsum qis dua 0.38, thiab cov khoom siv khi tsis tuaj yeem tshaj 500 kg / m³ vim yog cuam ​​tshuam ntawm pob zeb shrinkage. Qhov no txiav txim siab tias cov dej yuav tsum tsis pub tshaj 190 kg / m³. Xws li kev sib xyaw ua ke, thaum ntsuas kev ntws tau siv txoj kev poob qis, yuav muaj tus nqi ntawm 0 mm, qhia tias tsis muaj dej ntws thiab qhuav, txhav pob zeb yuav tsum muaj zog txhua yam kev co rau compaction. Cov txheej txheem kev tsim vaj tsev ib txwm tsis tuaj yeem ua tiav qhov sib xyaw thiab sib xyaw nrog cov khoom sib xyaw. Yog tias tsis hloov qhov sib xyaw ua ke, ntxiv qhov tsim nyog ntawm cov dej reducer tuaj yeem kho qhov poob rau 180-220 hli, txhim kho cov yas ntawm cov pob zeb. Lub luag haujlwm tseem ceeb ntawm cov dej reducers yog txhawm rau ua kom cov pob zeb ntws tsis tau hloov pauv qhov sib xyaw ua ke, yog li txhim kho plasticity.

Muaj ntau cov lus hais txog cov pob zeb ua dej txo qis, tab sis peb ntseeg tias kev ntxiv cov dej kom tsim nyog yam tsis tau hloov cov pob zeb sib xyaw ua ke tuaj yeem ua kom cov dej ntws tau zoo thiab txhim kho cov yas ntawm cov pob zeb, ua rau kev tsim kho yooj yim dua. Qhov no yog lub luag haujlwm tseem ceeb ntawm cov dej reducers hauv pob zeb. Los ntawm kev siv cov cuab yeej no thiab kho cov pob zeb sib xyaw ua ke, peb tuaj yeem ua tiav kev siv dej tsawg, txuag cement, lossis muaj zog ntxiv.